Spring



June 16, 1925 r H. W. SANFORD SPRING Filed July- 28, 1920 2 $heets-Sheec 1 Pateated June 16, 1925.

more era-res: Perrier orma HUG-Bl WHEELER SAN'FURQ, 0F. KNOXVILLE, TENNESSEE.

SPRING.

Application filed July es,

This invention relates to springs, and more particularly to springs of the character illustrated and described in my prior Patent No. 1,217,507, dated February 27 ,1917, wherein a convoluted tube is employed,

the same being made up of a flexible sheet plate having transverse convolutions or corrugations provided with parallel walls and curved connecting-walls, and pressureresistance means. being positioned within the tube, the said resistance means taking the form of compressed air or other gases.

W hile the patented construction has proven, in actual service, to be efiicient and satisfactory, at thesame time it is difficult to secure the metallic convoluted tube or bellows of suiiicient length and suiiicient range of elasticity without involving some considerable expense, and the particular type of guiding means employed is also e2;- pensive, and it is the main object of the present invention to generally improve upon and simplify, as well as to reduce the cost of production, of springs of the character disclosed in my said prior patent.

It is a further object of the invention to provide in operativeassociati-on with a spring of the character under consideration, means for applying same to vehicles, particularly motor vehicles, either at the front or rearaxles, or both at the rear and front axles, whereby to impart a leverage to the bellows, which decreases the necessary expansion and contraction under the movement of the car axle, and, thereby permits of the use ofa shorter bellows with correspondingly increased internal air pressures per square inch, and which at the same time simplifies the guiding means and reduces to a material extent the cost of production.

It is a further object of the present invention to provide a spring of the character under consideration which may be used in connection with, or independent of, the steel spring of either the top or bottom member,

we! F assesof the usual vehicle springs, or with rigid members teking the place of boththe top and bottom members of the usual bqw fina se as ay b s m eeSfide i f eie part cular instance;

Another obj. ct of the invention is to make possible, if; desired, an increase in the effective wheel base of the car to a lengtl'i considerably in excess of the distance between the centers of the front and rear axles; that is, to say, as far asv the car body is 0011- Qerned, tie agile mot-ion may be appliedto the car od-y at a point not immediately above the axle centers, asin the ordinary steel springconstruction, but at; apoint at, each. end further from the center of the wheel base thanthe axle center,

Other lmprovements and novel details in the construction and arrangement of the parts, will be appreciated from the description tov follow, which, for a clear understanding of the invention, is to be, considered in connection. with the accompanying drawings wherein isdisclosed, for the purpose of illustration,a convenient and satisfactory embodiment of the invention.

In the drawings, Figure 1 is a side elevation of the improved spring and rear axle application i Figure 2 is a sectional elevation of the spring removed from its axle connecting means;

Figure 3 is a transverse section substantially on the line 33 of Figure 2; and

Figure 4- is a transversesection'snbstan tially on the line 414: of Figure 2.

YVith more particular reference to the drawings, wherein like reference numerals refer to corresponding parts throughout the several views, 1 designates generally the rear end of the body portion of a vehicle, broken away, and 2, therear axle of the vehicle. Interposed between the body portion and the axle there is provided, in the usual construction, an upper steel spring and a lower steel spring, the upper steel spring being connectat its inner end to the framework ,of the body, and the lower steel spring at its inner end to the axle, and the steel springs at their opposite or rear ends being hingedly connected to one another, as by a suitable coupling pin.

It is proposed tak advantage, desired, of, this ordinary type of spring construction, and to interpose between the members of the spring a metal lie bellows type of spring, the bellows being arranged preferably at a point at the rear of and at the front of the body portion of the vehicle. While, as stated, the ordinary spring construction may be used to advan tage in connection with the air spring, at

the same time it may be desirable, and in some instances is desirable, to utilize in lieu of the ordinary spring members more substantial and comparatively rigid cast steel bracket members, in view of the fact that the metallic bellows spring herein contemplated would sufliciently take care of the necessary yieldability without the utilization of supplen'iental spring action incident to the ordinary spring members and with possibly less rebound.

Therefore, in the present embodiment of the invention, as illustrated, in lieu of the ordinary spring members, I provide a top cast steel bracket 3 to take the place of the ordinary spring member, said bracket having an upwardly curved securing part iat its forward end whereby to be secured in any desired manner as by means of bolts 5 to the under surface of the car or frame of the latter. The top steel bracket has a downwardly curved rear end 6 adapted to be hingedly connected as by a pintle 7 to the rear end of a bottom cast steel bracket 8, which latter at its inner end has a segn'iental part 9 adapted to be positioned over the rear axle, a substantially U-shaped eo-oper atiug member 10 engaging over the under surface of said axle and being secured at its flanges 11 to the bracket 8 as by means of the removable bolts 12. The bottom bracket 8 and (Jo-operating member 10 when secured in place, connect the lower bracket with the axle, so as to provide a fixed bearing at this point.

Arranged to be interposed between the top and bottom steel brackets 3 and 8, or between the top and bottom members of the usual spring positioned between the vehicle body and axle, is an air spring of the bellows type, details of which will now be described.

let is a sheet metal tube, preferably formed of a single piece of metal, which may be spun or otherwise shaped to form horizontally-disposed annular convolutions, of sufficient width to allow considerable flexibility of the convolutions, to the end that said tube may be compressed by end wise pressure or lengthened by a reverse pressure. Arranged at the top and bottom of said tube are annular ring-shaped members 15 and 16, respectively, substantially L-shaped in cross section, the horizontal flange of said rings being adapted to be in contact with annular integral horizontal extensions 17 and 18 of the top and bottom convolutions, respectively, of the corrugated tube 14. The vertically-disposed flanges of the ring-shaped members 15 and 16 have interiorly threaded portions 19 and 20, respectively. The upper head member, taking the form of a horizontally-disposed plate or disc 21, has circumferential threads 22 adapted to cooperate with the threads 19 of the upper ring, and when said plate is rotated to its seat, or to a point in contact with the bell -ws extension 17, the latter will be tightly secured in place on the horizontal flange of the upper ring, forming a substantial packing between the ring and the head plate, and rendering the joint between these parts substantially airtight.

A lower head 23 is also provided, the same including a horizontally-disposed annular section 23 having a circumferential. thread-- ed portion to co-operate with the threads of the lower ring member 16, and when threaded to seated position being adapted to firmly secure the lower horizontal extension of the corrugated tube in place. Like the top end of the tube, this lower end of the tube when seated constitutes in effect a substantial packing at the oint between the lower head and the lower ing member 16, thereby rendering this joint also airtight. Connecting with the horizontal flanged portion 23" of the lower head is a substantially verticallydisposed downwardly-projecting annular part 24, the inner surface of which preferably tapers inwardly from the top to the bottom thereof, as indicated at 25. Connecting with the lower end of the tapered annular part, or wall, 24, is a bottom wall 26, the inner surface of which is substantially convex, and at its center has an upwardly-projecting bearing portion 27.

The top and bottom heads, 21 and 23, respectively, are conveniently formed of cast steel. The top head has a flanged tubular portion 28, conveniently integral therewith and depending therefrom at a point within the upper end of the tapered annular portion, 24, of the lower head and in substantial vertical alignn'ient with the lower end of said annular portion 24. The tubular projection, 28, projects to a point adjacent the lower end of the corrugated tube 14: when in expanded or extended condition, and the lower end of the projection 28 has a tapered inner surface, 29, forming a sul'istantially pointed lower terminal for said tubular projection 28. The inner surface of the projection 28 conveniently inclines outwardly from its top to a point slightly spaced above the tapered portion 29, and connects with the latter by a substantially vertically-dis posed threaded section 30, into which is adapted to be threaded suitable casting 31, having a centrally-disposed opening, 32, surrounded by an upwardly-projeeting tubular member 33. The tubular wall 28 proi in sistance means vides an eli'ective guiding and supporting means for the inside of the bellows, thereby preventing possibility of excessive horizontal play or Warping of the bellows, and this projection: also acts as the annular Wall of an internal air and oil chamber, the topand bottom of which chamber are formed by the top casting 2'1 and" the casting 33. Thread ed to the bearing portion 27, 01 the lower casting, is What may be termed a reactionand-guiding pin 34, the latter being threaded as at to the bearing for vertical adjust ment and terminating at its upper end in an enlai d head 36. This reaction-and-guide pin loosely projects through the opening 32 andterninates at a point spaced above the bearing 33, and surrounding said bearing, and interposed between the disc 31 and the enlarged head 36 of the reaction-andgnide pinis a suitable compression spring 37. The reaction-and-guide pin 34, together with the compression spring 3'7, prevent an excessive expansion of the spring to a point that would injure the flexible bellows, and also provides against undue expansion Without undue abruptne-ss and incidental shock, since the compression action of this spring 37 is gradually brought into play to resist the expansion. This pi n also acts, as a means for guiding the relativemovemerit between the top and bottoml leads, 21

and 23, and it is to be borne in mii idthat with this in view the pin may be as strong and rigid as the requirements demand, but

i in the present application of the invention,

as illustrated, the relative motion of the two heads 21 and: 23, is controlled sutficiently effectively by the relation of the top and bottom brackets 3 and 3, between Which the bellows spring is interposed.

As in my prior patent, above alluded to, it is proposed to employ, in co-o-perative associationfwitl i the corrugated or bellows ma up ot spr an. internal pressure-resuchas air or oil, or both air and oil',and in the present embodiment of invention, the chamber'boun-ded by the .s 21,28, and 31 serves. as' a rigid comprcssion chamber inside the elastic compression chamber formed between the outside 0:523 and inside of bellows above oil level. To this end, a suitable automatic air-valve, not necessary to illustrate or describe in detail, but generally indicated by the reference numeral 33, is provided in asuitable valve plug 39 threaded to an interior threaded opening; conveniently in the top casting 2 The valve plug 39' is of any desired construction adapted to be engaged by a compressed air pump or the like, \vherebyan air spring is blown up tethe desired internal pressure. The opening for the valve plug 39, when thelatter is. removed, serves as a convenient manner of placing within the spring a suitable. quantity of oil, the normal level of which, When the spring is in equilibrium holding up the load on it, is generally indicated: by the letters A A, and when. the spring is further compressed, such level is indicated by the characters lit-B. It is understood, of course, that the oil is inserted prior to the insertion of the air undcr compression. An air by-pass opening of relatively small area is provided at 40 adjacent the upper end of the tubular projection 23 which constitutes the annular Wall of the conipre sion chamber, and a suitable spring-controlled check-valve 41 is provided for an. opening 42 in thevvall ot the projection 28 adjacent the top but preterably spaced below the air by-pass opening 40. The top casting 21 of the spring is provided with an apertured central projection 43, and the top steel bracket 3 is provided with apertured depending lugs, or ears, 44, one to engage over each side of the projee tion 43 of the spring- Whereby the apertures in the cars 44 and projection 43 may register and receive a suitable securing pin 45. Projecting from the central portion 25 of the lower head are apertured lugs 46 adapted. to engage over opposite surfaces oi. the lower steel-bracket 8, Which latter has an apertured lug 47, the aperture of Which is adapted to register With the apertures in the lugs 46 of the spring member and to be engaged by a suitable connecting pin 43..

In operation, it will be observed that the corrugated sheet metal tube is compressed, it will be protected from undue lateral movement, and the bellows will not be permitted toivarp except as allowed to do so by the Wall of the compression chamber, and the position of thew-all 23 with respect to the bellows, and in relation to the perpendicular axis of the air spring, is maintained primarily through the medium of the fulcrum pin 7, which, of course, will be assisted by the guiding connection between the pin 34 and its extended bearing 33. Theside and bottom Walls surrounding the compression chamber serve as means for stopping excessive compression of the air spring by imprisoning the oil gradually in the lower concave s 'tion 25 of the lower head 23, so that at a ,tain point in the extreme compression, the oil in this concave space will be unable to escape freely, and thus a retarding force is applied against further compression, which force will gradually build up greater and greater and finally entirely interrupt all further compression. Until this point reached, howeven the compression of the spring is a gradual one, thus avoiding undue strains and shocks incident to sudden stopping. As the pressure is relieved, the corrugated tube naturally expands, but excessive expansion and sudden expansion is avo ded in vievv of the compression spring 37, designed to take Lil care of the reaction by resisting the expansion. In the compression of the corrugated spring member or bellows, air, and a certain amount of oil, will pass freely into the compression chamber formed by the walls 21, 28, and 31, as the oil level rises on the outside of said chamber. During expansion of the spring, the air will pass back into the outer chamber sin-rounding the compression chamber through the small air inlet port 40, and the relative degree of the passage of the air may, of course, be controlled by the size of said port 40. The oil that passes through the check-valve il will gradually reach its normal level by passing gradually through the bearing 83 and the disc 31 for the pin It has been suggested by certain parties skilled in the art, that certain advantages accrue from increasing the eiiective wheel base of a motor vehicle to a length in excess of the distance between the front and rear axles, and the present application of my device ei'l'ectively takes care of any mechanical advantages incident to this arrange; ment. The air spring arrangement contemplated herein will provide for a longer wheel base with the further advantage of the air spring suspension alone, or a combination of air and steel spring suspension.

It the steel spring is used in lieu of the brackets 3 and 8, or of either of them, in combination with the air spring herein contemplated, the point of application of its force to the car body is identical with that of the air spring, that is, on the pin by which the air spring is attached to the top member.

lVhile the invention is illustrated and described in operative association with the rear end of the vehicle and the rear axle, it is understood, of course, that it desired the same construction may be readily e'tl'ectively applied to the front end of the vehicle and the front axle, by reversing the position of the mechanism.

As a protecting medium for the metallic bellows construction, the upper bracket member 3 is preterably provided with depending side tianges adapted to overlie the sides of the bellows, as illustrated more particularly in Fig. 1. These flanges may be formed of steel and may be cast integral. with the upper steel bracket, if desired.

It should be borne in mind that it is en tirely feasible and may, in some instances, be considered desirable, to employ in connection with the spring members abovedescribed, another rigid or spring member connecting the axle 2 with the car body, at the rear end of the car. This member would connect the axle with the car body preterably at a point in frontof the axle, somewhat after the fashion of ordinary tull elliptical springs. This auxiliary spring conneetion will assist in holding the axle in position and prevent side sway, since twice the leverage against side sway would thereby result.

lVithout the use of this auxiliary member, the tendency oi the body to sway sidewise is resisted by the fulcrum pin 7, whereas if another member is connected with the car body in front, as with the ordinary full, elliptical spring, the body would be more eliectively maintained in relation to the axle with less strain on the pin 7. It is obvious, or course, that the same results would be accomplished by the employment of the auxiliary connection at the front end of the car.

VVhat- I claim is:

1. A. spring attachment for vehicles, comprising an upper horizontal bracket, having a downward projection at its rear end and adapted to be connected at its forward end to the vehicle body, and a lower horizontal bracket member pivoted to the downward projection of the upper bracket member and adapted to be connected at its opposite end to an axle of the vehicle, a sheetmetal air bellows construction interposed between and secured to the upper and lower bracket members, and depending flanges on the upper bracket member adapted to normally extend below the upper end of the bellows and on opposite sides thereof.

2. A spring attachment for vehicles comprising an upper horizontal bracket, having a downward projection at its rear end and adapted to be connected at its forward end to the vehicle body, and a lower horizontal bracket member pivoted to the downward projection of the upper bracket member and adapted to be connected at its opposite end to an axle of the vehicle, a sheet metal air bellows construction interposed between and secured to the upper and lower bracket members, and depending flanges on the upper bracket member adapted to normally extend below the upper e -d of the bellows and on opposite sides thereof, the said bellows being disposed between the brackets at a point spaced outwardly be yond the normal wheel base of the car.

3. A spring comprising a vessel having rigid top and bottom walls and transversely convoluted metallic side walls yieldable along the lines of the vessels collapse, a substantially closed chamber depending trom the top wall, and oil within the tube adapted to be displaced in the downward movement of said chamber.

4. A spring comprising a vessel having a rigid top wall and a rigid bottom wall, and a transversely convoluted metallic side wall yieldable along the lines of the vessels collapse, a chamber depending from the top wall at a point within the side walls of the vessel, said chamber being formed by a tubular side wall and a bottom wall, and the rigid bottom wall of the vessel having a depending part of slightly greater diameter formed by said internal'tubular wall, and

a guide pin projecting upwardly from the bottom .plate and through a central opening in the bottom wall of the internal chamber.

'6. In a spring construction, thecombination of a top plate and a lower plate, and a tubular side wall forming with said plates an air-tight chamber, the side wall being transversely convoluted and elastic lengthwise, an internal tubular wall depending from the top wall at a point within the side wall, and a closed bottom for the chamber formed by said internal tubular wall, a guide pin projecting upwardly from the bottom plate and through a central opening in the bottom wall oi'lthe internal chamher, and a spring interposed between the upper end of said guide wall and the bot tom member of the internal chamber.

7. In a spring construction, thecombinw tion oil a top plate and a lower plate, and a tubular side wall forming with said plates an air-itight chamber, the side wall being transversely convoluted and elastic lengthwise, means 'torming a compressed air chamber comprising a .tubularside wall projecting from the top plate and terminating at a point above. the bottom plate, and a bot tom wall seeured to said tubular wall,means for theintroductionof air and oil into the chamber formed by the spring member, and the internal tubular wall having anhair bypass opening and a valve-control oil opening.

8. In a spring construction, the combination of a vessel adapted to contain compressed air and oil, said vessel comprising a top plate, a bottoin plate, and a tubular corrugated and yieldable side wall connecting said plates to form an air-tight cham-' her, a tubular wall projecting downwardly from the top plate at a point adjacent the innermost part'of the corrugated side wall, and the bottom plate having a depression, the side wall oi which gradually tapers downwardly and inwardly, and the smaller diameter of said tapered wall being approximately that oi the tubular projection from the top plate.

9. In a spring construction, the combination of a vessel adapted to contain compressed air and oil, said vessel. comprising a top ,plate, a bottom plate, and a tubular corrugated and yieldable side wall connecting said plates to form an air-tight chamber, a tubular wall projecting downwardly from the top plate at a point adjacent the innermost part of the corrugated side wall, and the bottom plate having a depressiomthe side wall of which gradually tapers clownwardly and inwardly, and the smaller diameter of said tapered wall being approxi mately that of the tubular projection from the top plate, and the tubular projection of the-top plate having a substantially pointed lower terminal.

10. lna spring constructiomthe combination of a vessel adapted to contain compressed air and oil, said vessel comprising a top platepa bottom plate, and a tubular corrugated .and yieldable side wall connecting said plates to l'orm an air-tight chamber, a tubular wall projecting downwardly from the top plate at a point adjacent the innermost .part of the corrugatedside wall, and the bottom plate having a depression, the side wall of which gradually tapers downwardly and inwardly, and the smaller diameter oi said tapered wall being approxiinately that of the tubular projection from the top plate, a bottom wall for said tubular projection, and a pin projecting lupwardly from said depressed portion of the bottom plate and loosely passing through a central aperture in the bottom wall of the tubular projection.

l1. Ina spring construction, the combination of a vessel adapted to contain compressed air and oil, said vessel comprising a top plate, a bottom plate, and a tubular corrugated and yieldable side wall connecting said plates to form an airtight chamber, a'tubular wall projecting downwardly from the top plate at a point adjacent the innermost'part ot the corrugated side wall, and the bottom plate having a depression, the side wall of which graduallytapers downwardly and inwardly, and thesmaller diameter of said tapered wall being approximately that of the tubular projection from the top plate, a bottom wall for said tubular projection, a pin projecting upwardly from said depressed portion of the bottom plate and loosely passing through a central aperture in the bottom wall of the tubular projection, said pin projecting the headed upper end, and a spring interposed between said headed upper end and the bottom wall of the tubular projection.

12. Ina spring construction of the character described, the combination of a top plate having a central upwardly projecting apertured securing member, and a lower plate having a downwardly projecting apertured securing member, an upright tubularcorrugated flexible side wall uniting said plates and forming therewith an air-tight (.hamber, one of said plates having a normally closed inlet for the introduction of air under pressure and oil, the lower plate having a depressed portion forming an oil well, and a top plate having a tubular proj ection adapted in the relative sliding movement of the plates to engage in said well, said tubular projection terminating at a point normally slightly above the bottom plate at its highest point.

13. In a spring construction of the character described, the combination of a top plate having a central upwardly projecting apertured securing member, and a lower plate having a downwardly projecting apertured securing member, an upright tubular corrugated flexible side wall uniting said plates and forming therewith an airtight chamber, one of said plates having a norn'ially closed inlet for the introduction oi? air under pressure and oil, the lower plate having a depressed portion forming an oil well, a top plate having a tubular projection adapted in the sliding movement of the plates to engage in said well, said tubular projection terminating at a point normally slightly abovethe bottom plate at its highest point, and a bottom wall for said tubular projection.

l l. In a spring construction of the character described, the combination of a top plate having a central upwardly projecting apertured securing member, and a lower plate having a downwardly projecting apertured securing member, an upright tubular corrugated flexible side wall uniting said plates and forming therewith an air-tight chamber, one of said plates having a normally closed inlet for the introduction of air under pressure and oil, the lower plate having a depressed portion forming an oil well, a top plate having a tubular projection adapted in the sliding movement of the plates to engage in said well, said tubular projection terminating at a point normally slightly above the bottom plate at its highest point, a bottom wall for said tubular projection, and a guide pin projecting upwardly from thebottom plate and loosely passing through the bottom wall of said tubular projection.

15. In a spring mechanism of the character described, the combination of end plates, an upright sheet metal tube trans versely convoluted and elastic lengthwise and substantially nonelastic transversely said tube being secured to the end plates so as to provide with the latter a substantially air-tight chamber, and said chamber being provided with a valved inlet, and internal yieldable means for resisting sudden expansion of the tube.

16. In a spring mechanism of the character described, the combination of two end plates and a connecting tube of transversely convoluted flexible sheet metal construction, whereby to permit of expansion of the tube, means "for preventing the tube from buckling sidewise between its ends, and means for limiting the expansion of the tube, said means including a spring arranged within the tube and operatively connected respectively with the end plates of the tube.

17. In a spring mechanism of the character described, the combination of two end plates and a connecting tube of transversely convoluted flexible sheet metal construction, whereby to permit of expansion 01 the tube, means for preventing the tube from buckling sidewise between its. ends, and means for limiting the expansion of the tube, said lastmentioned means being adjustable.

18. A spring comprising a vessel having a rigid top wall and a rigid bottom wall, and a transversely convoluted metallic side wall yieldable along the lines of the vessels collapse, a chamber depending from the top wall and confined within the side walls of the vessel, a guide member extending upwardly from the bottom wall of the vessel and extending through the bottom of the chamber to prevent lateral movement thereof, and a fluid within the vessel adapted to be displaced in the downward movement of the chamber.

In testimony whereof I hereunto aflix my signature in the presence of two witnesses.

HUGH IVHEELEP SANFORD.

lVitnesses H. E. LITTLEFIELD, WV. J. BACON. 

